1. Field of the Invention
The present invention relates to a method of dynamically balancing cylindrical rotors for pressure wave superchargers and the like, as well as a device which may be used to carry out the method.
2. Description of the Related Art
It is widely known in the art that various kinds of rotors subjected to rotation at a high revolutional speeds encounter a serious problem that even a slight dynamic unbalance induces a significant vibration whereby a smooth operation becomes impossible. Hence, particularly when the rotor comprises a ceramic material, as is the case in superchargers for automobiles and the like, in order to minimize the dynamic unbalance and to thereby dynamically balance the rotor, it has been a conventional practice to carry out a necessary correction of the dynamic unbalance after the shaped body with the desired configuration of the rotor has been subjected to firing, by machining the sintered body and removing therefrom a predetermined quantity of the material, generally with the machining axis which lies on the geometrical center axis of the body.
However, such a conventional machining process does not yield an effective dynamic unbalance correction since, when producing rotors comprising ceramic materials, the sintered body has been subjected to strains during the shaping and/or firing steps, and the geometrical center axis of the sintered body tends to be slightly offset from the predetermined rotational axis of the rotor. Stated otherwise, correction of the dynamic unbalance of the rotor body with reference to the geometrical center axis of the rotor body does not necessarily result in that an accurate dynamic balancing of the rotor has been completed with reference to the rotational axis of the rotor. Needless to say, rotors without a satisfactory dynamic balance cannot be used as a product for practical purposes.